http://android-dev-log.ldblog.jp/archives/11346611.html

fb2bmp.c

/************************************************/
// 2012.07.12
// Author: pentux
/************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PRINT_ERR(str) { fprintf(stdout, str); }

// ヘッダのサイズ
#define FILE_HEADER_SIZE 14
#define WIN_HEADER_SIZE 40
#define OS2_HEADER_SIZE 12

// 1画素あたりのバイト数とピクセル数
#define PXL_BYTE 4
#define BIT_COUNT (PXL_BYTE*8)

// 画面サイズの定義
#define QVGA_X 320
#define QVGA_Y 480
#define WVGA800_X 480
#define WVGA800_Y 800

// 画像のサイズ
typedef enum { QVGA, WVGA800 } IMG_SIZE;

// BMP の種類
typedef enum { WIN, OS2 } BMP_TYPE;

// 型変換
typedef unsigned char byte;
typedef unsigned int uint;


// 内部関数群
byte *read_byte_data(char *path, uint *size);
uint write_byte_data(char *path, byte *data, uint size);
BMP_TYPE select_bmp_type(char *type);
IMG_SIZE select_img_size(char *size);
byte *add_bmp_header(uint *bmp_data_size, byte *data, uint size, BMP_TYPE bmp_type, IMG_SIZE img_size);
byte *create_header(uint *header_data_size, uint data_size, BMP_TYPE bmp_type, IMG_SIZE img_size);
uint get_info_header_size(BMP_TYPE bmp_type);
byte *create_info_header(BMP_TYPE bmp_type, IMG_SIZE img_size);
uint get_img_size_x(IMG_SIZE img_size);
uint get_img_size_y(IMG_SIZE img_size);
byte *inverse_top_bottom(byte *data, uint data_size, uint width);
byte *convert_fb_data(byte *data, uint data_size);
void convert16to32(byte dst[], byte src[]);


/**
 * Main
 */
int main(int argc, char *argv[]){
  if(argc != 5){
    printf("Usage: add_bmp_header [dst_path] [src_path] [bmp_type] [bmp_size]\n"
	   "\tbmp_type : WIN or OS2\n"
	   "\tbmp_size : WVGA800, QVGA\n");
    return 1;
  }

  char *dst_path = argv[1];
  char *src_path = argv[2];
  BMP_TYPE bmp_type = select_bmp_type(argv[3]);
  IMG_SIZE img_size = select_img_size(argv[4]);

  uint data_size = 0;
  byte *data = read_byte_data(src_path, &data_size);
  byte *tmp_data = NULL;

  // Convert frame buffer data.
  tmp_data = convert_fb_data(data, data_size);
  if(tmp_data == NULL){
    PRINT_ERR("Error of converting fb data.\n");
    if(data != NULL){
      free(data);
    }
    return 1;
  }
  free(data);
  data = tmp_data;

  // Inverse bmp data
  tmp_data = inverse_top_bottom(data, data_size, get_img_size_x(img_size));
  if(tmp_data == NULL){
    PRINT_ERR("Error of inversing original bmp data.\n");
    if(data != NULL){
      free(data);
    }
    return 1;
  }
  free(data);
  data = tmp_data;

  // Add header
  uint bmp_data_size = 0;
  byte *bmp_data = add_bmp_header(&bmp_data_size, data, data_size, bmp_type, img_size);

  write_byte_data(dst_path, bmp_data, bmp_data_size);

  free(data);
  free(bmp_data);

  return 0;
}

byte *convert_fb_data(byte *data, uint data_size){
  byte *converted = (byte *)calloc(sizeof(byte), data_size);
  uint i = 0;
  for(i = 0; i < data_size/2; i+=2){
    convert16to32(converted+i*2, data+i);
  }
  return converted;
}

/**
 * Convert RGB565 into RGB888
 *   dst:4byte, src:2byte
 */
void convert16to32(byte dst[], byte src[]){
  uint tmp = src[0] + (src[1] << 8);
  byte b = (tmp & 0x001F) >> 0;
  byte g = (tmp & 0x07E0) >> 5;
  byte r = (tmp & 0xF800) >> 11;
  dst[0] = b * 255/32;
  dst[1] = g * 255/64;
  dst[2] = r * 255/32;
  dst[3] = 0;
}

/**
 * Inverse order data between top and bottom.
 */
byte *inverse_top_bottom(byte *data, uint data_size, uint width){
  byte *inversed = (byte *)malloc(sizeof(byte) * data_size);
  uint i = 0;
  uint height = data_size / width / PXL_BYTE;
  for(i = 0; i < height; i++){
    uint j = 0;
    for(j = 0; j < width*PXL_BYTE; j++){
      inversed[(height-1-i)*width*PXL_BYTE + j] = data[i*width*PXL_BYTE + j];
    }
  }
  return inversed;
}

/**
 * Create BMP header info.
 */
byte *create_header(uint *header_size, uint data_size, BMP_TYPE bmp_type, IMG_SIZE img_size){
  (*header_size) = FILE_HEADER_SIZE + get_info_header_size(bmp_type);
  uint all_size = data_size + (*header_size);
  byte mask = 0xFF;

  // file header
  byte file_header[FILE_HEADER_SIZE] = {0};

  // File Type
  file_header[0] = 'B';
  file_header[1] = 'M';

  // File Size
  file_header[2] = all_size & mask;
  file_header[3] = (all_size >> (sizeof(byte)*1*8)) & mask;
  file_header[4] = (all_size >> (sizeof(byte)*2*8)) & mask;
  file_header[5] = (all_size >> (sizeof(byte)*3*8)) & mask;

  // Reserved
  file_header[6] = 0;
  file_header[7] = 0;
  file_header[8] = 0;
  file_header[9] = 0;

  // Offset from TopData to ImageData
  file_header[10] = (*header_size) & mask;
  file_header[11] = ((*header_size) >> (sizeof(byte)*1*8)) & mask;
  file_header[12] = ((*header_size) >> (sizeof(byte)*2*8)) & mask;
  file_header[13] = ((*header_size) >> (sizeof(byte)*3*8)) & mask;

  // info header
  byte *info_header = create_info_header(bmp_type, img_size);

  // Concat file_hader and info_header
  byte *header_data = (byte *)malloc(sizeof(byte) * all_size);
  memcpy(header_data, file_header, sizeof(byte) * FILE_HEADER_SIZE);
  memmove(header_data+sizeof(byte)*FILE_HEADER_SIZE, info_header, sizeof(byte)*get_info_header_size(bmp_type));

  return header_data;
}

uint get_img_size_x(IMG_SIZE img_size){
  switch(img_size){
  case QVGA: return QVGA_X;
  case WVGA800: return WVGA800_X;
  default: return -1;
  }
}

uint get_img_size_y(IMG_SIZE img_size){
  switch(img_size){
  case QVGA: return QVGA_Y;
  case WVGA800: return WVGA800_Y;
  default: return -1;
  }
}

byte *create_info_header(BMP_TYPE bmp_type, IMG_SIZE img_size){
  byte mask = 0xFF;
  byte *info_header = NULL;
  info_header = (byte *)malloc(sizeof(byte)*get_info_header_size(bmp_type));
  uint x = get_img_size_x(img_size);
  uint y = get_img_size_y(img_size);

  switch(bmp_type){
  case  OS2:
    // Size
    info_header[0] = OS2_HEADER_SIZE;
    info_header[1] = 0;
    info_header[2] = 0;
    info_header[3] = 0;

    // Width
    info_header[4] = x & mask;
    info_header[5] = (x >> (sizeof(byte)*1*8)) & mask;

    // Height
    info_header[6]  = y & mask;
    info_header[7]  = (y >> (sizeof(byte)*1*8)) & mask;

    // Planes
    info_header[8] = 1;
    info_header[9] = 0;

    // BitCount
    info_header[10] = BIT_COUNT;
    info_header[11] = 0;

    break;

  case WIN:
    // Size
    info_header[0] = WIN_HEADER_SIZE;
    info_header[1] = 0;
    info_header[2] = 0;
    info_header[3] = 0;

    // Width
    info_header[4] = x & mask;
    info_header[5] = (x >> (sizeof(byte)*1*8)) & mask;
    info_header[6] = (x >> (sizeof(byte)*2*8)) & mask;
    info_header[7] = (x >> (sizeof(byte)*3*8)) & mask;

    // Height
    info_header[8]  = y & mask;
    info_header[9]  = (y >> (sizeof(byte)*1*8)) & mask;
    info_header[10] = (y >> (sizeof(byte)*2*8)) & mask;
    info_header[11] = (y >> (sizeof(byte)*3*8)) & mask;

    // Planes
    info_header[12] = 1;
    info_header[13] = 0;

    // BitCount
    info_header[14] = BIT_COUNT;
    info_header[15] = 0;

    // Compression
    info_header[16] = 0;
    info_header[17] = 0;
    info_header[18] = 0;
    info_header[19] = 0;

    // Size of Image part
    info_header[20] = 0;
    info_header[21] = 0;
    info_header[22] = 0;
    info_header[23] = 0;

    // Pixel per Meter X
    info_header[24] = 0;
    info_header[25] = 0;
    info_header[26] = 0;
    info_header[27] = 0;

    // Pixel per Meter Y
    info_header[28] = 0;
    info_header[29] = 0;
    info_header[30] = 0;
    info_header[31] = 0;

    // Used palet num
    info_header[32] = 0;
    info_header[33] = 0;
    info_header[34] = 0;
    info_header[35] = 0;

    // Important palet index
    info_header[36] = 0;
    info_header[37] = 0;
    info_header[38] = 0;
    info_header[39] = 0;

    break;
  }

  return info_header;
}

uint get_info_header_size(BMP_TYPE type){
  switch(type){
  case WIN: return WIN_HEADER_SIZE;
  case OS2: return OS2_HEADER_SIZE;
  default:  return WIN_HEADER_SIZE;
  }
}

/**
 * Create BMP header and add on head of bmp binary data.
 *   args  : 
 *   return: 
 */
byte *add_bmp_header(uint *bmp_data_size, byte *data, uint data_size, BMP_TYPE bmp_type, IMG_SIZE img_size){
  if(data == NULL){
    PRINT_ERR("Error. No original byte data in add_bmp_header().\n");
    return NULL;
  }

  // create header data
  uint header_size = 0;
  byte *header_data = create_header(&header_size, data_size, bmp_type, img_size);

  // concat header_data and read binary data
  (*bmp_data_size) = header_size + data_size;
  byte *bmp_data = (byte *)calloc(sizeof(byte), (*bmp_data_size));
  memcpy(bmp_data, header_data, sizeof(byte)*header_size);
  memmove(bmp_data+sizeof(byte)*header_size, data, sizeof(byte)*data_size);

  return bmp_data;
}

BMP_TYPE select_bmp_type(char *type){
  if(!strcmp(type, "WIN")){
    return WIN;
  }else if(!strcmp(type, "OS2")){
    return OS2;
  }
  return WIN;
}

IMG_SIZE select_img_size(char *size){
  if(!strcmp(size, "QVGA")){
    return QVGA;
  }else if(!strcmp(size, "WVGA800")){
    return WVGA800;
  }
  return WVGA800;
}


/**
 * Read byte data from binary file.
 */
byte *read_byte_data(char *path, uint *size){
  if(path == NULL){
    PRINT_ERR("Read file path error.\n");
    return NULL;
  }

  FILE *fp = NULL;
  if((fp = fopen(path, "rb")) == NULL){
    PRINT_ERR("Reading file open error.\n");
    return NULL;
  }

  (*size) = 0;
  byte d = 0;
  byte *data = NULL;
  byte *tmp_data = NULL;
  while(fread(&d, sizeof(byte), 1, fp) == 1){
    (*size) += 1;
    tmp_data = (byte *)realloc(data, sizeof(byte)*(*size));
    if(tmp_data == NULL){
      PRINT_ERR("Realloc Error.\n");
      if(data != NULL)
	free(data);
      return NULL;
    }
    data = tmp_data;
    data[*size-1] = d;
  }

  fclose(fp);

  return data;
}

/**
 * Write byte data into binary file.
 *   args  : target_file_path, write_data, write_data_size
 *   return: wrote data size
 */
uint write_byte_data(char *path, byte *data, uint size){
  if(path == NULL){
    PRINT_ERR("Write file path error.\n");
    return -1;
  }

  FILE *fp = NULL;
  if((fp = fopen(path, "wb")) == NULL){
    PRINT_ERR("Write file open error.\n");
    return -1;
  }

  uint i = 0;
  for(i = 0; i < size; i++)
    fwrite(data+i, sizeof(byte), 1, fp);

  fclose(fp);

  return i;
}